[patch 5/5] Apply the PG_sensitive flag to the CryptoAPI subsystem

From: Larry H.
Date: Wed May 20 2009 - 15:05:58 EST

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This patch deploys the use of the PG_sensitive page allocator flag
within the CryptoAPI subsystem, in all relevant locations where
algorithm and key contexts are allocated.

Some calls to memset for zeroing the buffers have been removed to
avoid duplication of the sanitizing process, since this is already
taken care of by the allocator during page freeing.

The only noticeable impact on performance might be in the blkcipher
modifications, although this is likely negligible and balanced with
the security benefits of this patch in the long term.

Signed-off-by: Larry H. <research@xxxxxxxxxxxxxx>

---
crypto/ablkcipher.c | 3 +--
crypto/aead.c | 5 ++---
crypto/ahash.c | 3 +--
crypto/algapi.c | 2 +-
crypto/api.c | 7 +++----
crypto/authenc.c | 2 +-
crypto/blkcipher.c | 11 +++++------
crypto/cipher.c | 3 +--
crypto/cryptd.c | 2 +-
crypto/gcm.c | 6 +++---
crypto/hash.c | 3 +--
crypto/rng.c | 2 +-
crypto/seqiv.c | 5 +++--
crypto/shash.c | 3 +--
14 files changed, 25 insertions(+), 32 deletions(-)

Index: linux-2.6/crypto/ablkcipher.c
===================================================================
--- linux-2.6.orig/crypto/ablkcipher.c
+++ linux-2.6/crypto/ablkcipher.c
@@ -35,14 +35,13 @@ static int setkey_unaligned(struct crypt
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cipher->setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
Index: linux-2.6/crypto/aead.c
===================================================================
--- linux-2.6.orig/crypto/aead.c
+++ linux-2.6/crypto/aead.c
@@ -33,14 +33,13 @@ static int setkey_unaligned(struct crypt
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = aead->setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
@@ -232,7 +231,7 @@ struct crypto_instance *aead_geniv_alloc
if (IS_ERR(name))
return ERR_PTR(err);

- inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL | GFP_SENSITIVE);
if (!inst)
return ERR_PTR(-ENOMEM);

Index: linux-2.6/crypto/ahash.c
===================================================================
--- linux-2.6.orig/crypto/ahash.c
+++ linux-2.6/crypto/ahash.c
@@ -138,14 +138,13 @@ static int ahash_setkey_unaligned(struct
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = ahash->setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
Index: linux-2.6/crypto/algapi.c
===================================================================
--- linux-2.6.orig/crypto/algapi.c
+++ linux-2.6/crypto/algapi.c
@@ -634,7 +634,7 @@ struct crypto_instance *crypto_alloc_ins
struct crypto_spawn *spawn;
int err;

- inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL | GFP_SENSITIVE);
if (!inst)
return ERR_PTR(-ENOMEM);

Index: linux-2.6/crypto/api.c
===================================================================
--- linux-2.6.orig/crypto/api.c
+++ linux-2.6/crypto/api.c
@@ -114,7 +114,7 @@ struct crypto_larval *crypto_larval_allo
{
struct crypto_larval *larval;

- larval = kzalloc(sizeof(*larval), GFP_KERNEL);
+ larval = kzalloc(sizeof(*larval), GFP_KERNEL | GFP_SENSITIVE);
if (!larval)
return ERR_PTR(-ENOMEM);

@@ -380,7 +380,7 @@ struct crypto_tfm *__crypto_alloc_tfm(st
int err = -ENOMEM;

tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
- tfm = kzalloc(tfm_size, GFP_KERNEL);
+ tfm = kzalloc(tfm_size, GFP_KERNEL | GFP_SENSITIVE);
if (tfm == NULL)
goto out_err;

@@ -476,7 +476,7 @@ struct crypto_tfm *crypto_create_tfm(str
tfmsize = frontend->tfmsize;
total = tfmsize + sizeof(*tfm) + frontend->extsize(alg, frontend);

- mem = kzalloc(total, GFP_KERNEL);
+ mem = kzalloc(total, GFP_KERNEL | GFP_SENSITIVE);
if (mem == NULL)
goto out_err;

@@ -592,7 +592,6 @@ void crypto_destroy_tfm(void *mem, struc
alg->cra_exit(tfm);
crypto_exit_ops(tfm);
crypto_mod_put(alg);
- memset(mem, 0, size);
kfree(mem);
}
EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
Index: linux-2.6/crypto/authenc.c
===================================================================
--- linux-2.6.orig/crypto/authenc.c
+++ linux-2.6/crypto/authenc.c
@@ -397,7 +397,7 @@ static struct crypto_instance *crypto_au
if (IS_ERR(enc_name))
goto out_put_auth;

- inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL | GFP_SENSITIVE);
err = -ENOMEM;
if (!inst)
goto out_put_auth;
Index: linux-2.6/crypto/blkcipher.c
===================================================================
--- linux-2.6.orig/crypto/blkcipher.c
+++ linux-2.6/crypto/blkcipher.c
@@ -161,7 +161,7 @@ static inline int blkcipher_next_slow(st

n = aligned_bsize * 3 - (alignmask + 1) +
(alignmask & ~(crypto_tfm_ctx_alignment() - 1));
- walk->buffer = kmalloc(n, GFP_ATOMIC);
+ walk->buffer = kmalloc(n, GFP_ATOMIC | GFP_SENSITIVE);
if (!walk->buffer)
return blkcipher_walk_done(desc, walk, -ENOMEM);

@@ -242,7 +242,7 @@ static int blkcipher_walk_next(struct bl
!scatterwalk_aligned(&walk->out, alignmask)) {
walk->flags |= BLKCIPHER_WALK_COPY;
if (!walk->page) {
- walk->page = (void *)__get_free_page(GFP_ATOMIC);
+ walk->page = (void *)__get_free_page(GFP_ATOMIC|GFP_SENSITIVE);
if (!walk->page)
n = 0;
}
@@ -287,7 +287,7 @@ static inline int blkcipher_copy_iv(stru
u8 *iv;

size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
- walk->buffer = kmalloc(size, GFP_ATOMIC);
+ walk->buffer = kmalloc(size, GFP_ATOMIC | GFP_SENSITIVE);
if (!walk->buffer)
return -ENOMEM;

@@ -366,14 +366,13 @@ static int setkey_unaligned(struct crypt
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cipher->setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
@@ -569,7 +568,7 @@ struct crypto_instance *skcipher_geniv_a
if (IS_ERR(name))
return ERR_PTR(err);

- inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL | GFP_SENSITIVE);
if (!inst)
return ERR_PTR(-ENOMEM);

Index: linux-2.6/crypto/cipher.c
===================================================================
--- linux-2.6.orig/crypto/cipher.c
+++ linux-2.6/crypto/cipher.c
@@ -30,14 +30,13 @@ static int setkey_unaligned(struct crypt
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = cia->cia_setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;

Index: linux-2.6/crypto/cryptd.c
===================================================================
--- linux-2.6.orig/crypto/cryptd.c
+++ linux-2.6/crypto/cryptd.c
@@ -196,7 +196,7 @@ static struct crypto_instance *cryptd_al
struct cryptd_instance_ctx *ctx;
int err;

- inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL | GFP_SENSITIVE);
if (!inst) {
inst = ERR_PTR(-ENOMEM);
goto out;
Index: linux-2.6/crypto/gcm.c
===================================================================
--- linux-2.6.orig/crypto/gcm.c
+++ linux-2.6/crypto/gcm.c
@@ -208,7 +208,7 @@ static int crypto_gcm_setkey(struct cryp
CRYPTO_TFM_RES_MASK);

data = kzalloc(sizeof(*data) + crypto_ablkcipher_reqsize(ctr),
- GFP_KERNEL);
+ GFP_KERNEL | GFP_SENSITIVE);
if (!data)
return -ENOMEM;

@@ -454,7 +454,7 @@ static struct crypto_instance *crypto_gc
if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
return ERR_PTR(-EINVAL);

- inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL | GFP_SENSITIVE);
if (!inst)
return ERR_PTR(-ENOMEM);

@@ -703,7 +703,7 @@ static struct crypto_instance *crypto_rf
if (IS_ERR(ccm_name))
return ERR_PTR(err);

- inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
+ inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL | GFP_SENSITIVE);
if (!inst)
return ERR_PTR(-ENOMEM);

Index: linux-2.6/crypto/hash.c
===================================================================
--- linux-2.6.orig/crypto/hash.c
+++ linux-2.6/crypto/hash.c
@@ -35,14 +35,13 @@ static int hash_setkey_unaligned(struct
unsigned long absize;

absize = keylen + alignmask;
- buffer = kmalloc(absize, GFP_ATOMIC);
+ buffer = kmalloc(absize, GFP_ATOMIC | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
ret = alg->setkey(crt, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return ret;
}
Index: linux-2.6/crypto/rng.c
===================================================================
--- linux-2.6.orig/crypto/rng.c
+++ linux-2.6/crypto/rng.c
@@ -32,7 +32,7 @@ static int rngapi_reset(struct crypto_rn
int err;

if (!seed && slen) {
- buf = kmalloc(slen, GFP_KERNEL);
+ buf = kmalloc(slen, GFP_KERNEL | GFP_SENSITIVE);
if (!buf)
return -ENOMEM;

Index: linux-2.6/crypto/seqiv.c
===================================================================
--- linux-2.6.orig/crypto/seqiv.c
+++ linux-2.6/crypto/seqiv.c
@@ -115,9 +115,10 @@ static int seqiv_givencrypt(struct skcip

if (unlikely(!IS_ALIGNED((unsigned long)info,
crypto_ablkcipher_alignmask(geniv) + 1))) {
- info = kmalloc(ivsize, req->creq.base.flags &
+ info = kmalloc(ivsize, (req->creq.base.flags &
CRYPTO_TFM_REQ_MAY_SLEEP ? GFP_KERNEL:
- GFP_ATOMIC);
+ GFP_ATOMIC)
+ | GFP_SENSITIVE);
if (!info)
return -ENOMEM;

Index: linux-2.6/crypto/shash.c
===================================================================
--- linux-2.6.orig/crypto/shash.c
+++ linux-2.6/crypto/shash.c
@@ -37,14 +37,13 @@ static int shash_setkey_unaligned(struct
int err;

absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
- buffer = kmalloc(absize, GFP_KERNEL);
+ buffer = kmalloc(absize, GFP_KERNEL | GFP_SENSITIVE);
if (!buffer)
return -ENOMEM;

alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
memcpy(alignbuffer, key, keylen);
err = shash->setkey(tfm, alignbuffer, keylen);
- memset(alignbuffer, 0, keylen);
kfree(buffer);
return err;
}
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Next message: Oleg Nesterov: "Q: put_user_try & co (Was: [PATCH 1/5] Split wait_noreap_copyout())"
Previous message: Steven Rostedt: "Re: [PATCH 0/1] sched: fix typo in sched-rt-group.txt file"
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